KR100680028B1 - Wasteheat recovery system applied for rto - Google Patents

Abstract

A waste heat recovering apparatus applied to an RTO is provided to prevent lowering of the incineration efficiency by circulating cooled exhaust gas to an inlet of the RTO. An RTO includes a main blower(100), RTO layers(200,220,240), and a combustion chamber(320). The RTO incinerates volatile organic compositions and bad odors. A waste heat recovering apparatus applied to the RTO includes a waste heat recovering heat exchanger(400), a first circulation blower(120), and a wind amount regulating valve(600). The waste heat recovering heat exchanger recovers the heat of the gas of high temperature which is discharged from the combustion chamber. The first circulation blower circulates the cooled gas discharged from the combustion chamber to the front and rear sides of the waste heat recovering heat exchanger. The wind amount regulating valve regulates the amount of gas passed through the waste heat recovering heat exchanger.

Description

Waste Heat Recovery System Applied to Regenerative Incinerators {WasteHeat Recovery System Applied for RTO}

1 is a process diagram of an exhaust gas waste heat recovery apparatus of a conventional heat storage combustion apparatus.

2 is a process diagram of a hot gas waste heat recovery apparatus of a conventional heat storage incinerator.

Figure 3 is a waste heat recovery apparatus process diagram applied to the heat storage incinerator according to an embodiment of the present invention.

Figure 4 is a waste heat recovery apparatus process diagram applied to the heat storage incinerator according to another embodiment of the present invention.

5 is a waste heat recovery apparatus process diagram applied to the heat storage incinerator according to another embodiment of the present invention.

 <Explanation of symbols for the main parts of the drawings>

100: main blower 120: first circulation blower

140: second circulation blower

200: first heat storage layer 220: second heat storage layer

240: third heat storage layer

300: Regenerative Incinerator (RTO) 320: Combustion chamber

340: With auxiliary combustion

400: waste heat recovery exchanger

500: pressure sensor 520: temperature sensor

540: food

600: air flow control valve 620: check valve

640: stack

700: Purge automatic valve 720: First heat storage layer purge and circulation valve

740: second heat storage layer purge and circulation valve 760: third heat storage layer purge and circulation valve

Field of technology

The present invention relates to a waste heat recovery apparatus used in a regenerative incinerator for incineration of VOC (volatile organic compounds) and malodorous gases (hereinafter referred to as organic malodorous gases).

The regenerative incinerator transfers the heat of the hot exhaust gas discharged after combustion from the combustion chamber from the upper part of the heat storage layer to the lower direction, and directly contacts the ceramic heat exchange medium, thereby accumulating the ceramic medium and exhausting the cooled gas to the atmosphere. The organic odor gas for incineration in the incinerator is moved from the bottom of the regenerated heat storage layer to the upper direction to be in direct contact with the ceramic medium, thereby preheating the organic odor to the combustion chamber 320 to incinerate the low energy type incineration system. Say.

The regenerative incinerator process consists of four parts, which will be briefly described below.

First is the preheating process. 3, 4, and 5, the heat storage incinerator composed of a 3Bed heat storage layer is illustrated as a preheating process in the first heat storage layer in the drawing. The organic odor gas flows into the heat storage incinerator through the main blower. Firstly, the first heat storage layer 200 is introduced into the lower portion, and is preheated through heat exchange with the heat-generated ceramic, thereby preheating to almost the combustion chamber temperature.

Second is the incineration process. Subsequent to the above process, when the organic odor gas is subjected to a preheating process and introduced into the combustion chamber, it is converted into carbon dioxide and water, which are harmless gases. This is called incineration process.

Third is the heat storage process. Following the above process, the hot gas incinerated in the combustion chamber is moved from the upper side to the lower side of the second heat storage layer, heating the ceramic, transferring heat to the second heat storage layer, and then cooling and finally discharging it to the stack. At this time, the final discharge temperature is different depending on the type of heat storage medium of the heat storage type incinerator and the heat storage medium heat storage amount than the temperature of the organic gas introduced through the initial main blower, but is generally about 40 ° C., that is, the gas flowing at room temperature 30 ° C. According to the heat storage effect of the heat storage type incinerator, the temperature rises to the combustion chamber temperature of 850 ° C., but is finally discharged at about 70 ° C., and the heat storage efficiency is about 95%.

Fourth is the purge process. Subsequent to the above process, a purge process is performed in the third heat storage layer. The heat storage layer of the preheating process and the heat storage process changes at regular intervals. If the first heat storage layer has been preheated for a certain time (approximately 15 to 200 seconds), the process returns to-> purge process-> heat storage process-> preheating process, which is repeated over and over again.

As such, the purge process between the preheating and the heat storage process is carried out by the organic odor gas in the heat storage layer during the preheating step, which continues the gas flow direction from the bottom to the top of the heat storage layer. If the direct conversion to the heat storage process of exhausting the burned gas into the air without going through the purge layer of the preheating step, the gas flow direction of the heat storage process moves from the top of the heat storage layer to the bottom to be finally discharged, The untreated gas remaining in the heat storage layer of the gas is discharged to the stack without passing through the combustion chamber, causing environmental pollution. Therefore, the purge gas is introduced into the bottom of the heat storage layer after the preheating step, and the untreated gas is sent to the combustion chamber after the top of the heat storage layer and incinerated, and finally discharged through the gas and condensation heat storage layer of the heat storage process. This is called a purge process. The purge gas uses a portion of the stack gas that is injected into the outside air or discharged after incineration in the prior art.

In the present invention, when the heat concentration of organic odor gas in the regenerative incinerator is high and the waste heat recovery of the combustion heat generated during the combustion process in the combustion chamber is necessary, recovering the waste heat in the hot gas state generated in the combustion chamber in the regenerative incinerator is a process characteristic. Developed more advantageously.

Conventional Techniques and Problems

1 is a process diagram of an exhaust gas waste heat recovery apparatus (application number: 10-1998- 0016607) of a conventional heat storage combustion machine.

Specifically, the combustion gas is used to heat the waste heat recovery heat exchanger by constructing a circulation line equipped with a waste heat recovery heat exchanger after inducing combustion of the gas in the combustion chamber or part of the incomplete combustion state to the auxiliary combustion chamber. The gas is connected to the auxiliary combustion chamber through a circulating blower to recover waste heat while the waste heat is partially recovered.

In this case, it is cooled to 350 ℃ in the furnace's furnace temperature of 850 ℃ and the heat dissipation loss of the main body of the machine can get about 59% of heat efficiency, but the heat equivalent of 350 ℃ is equivalent to 41% of waste heat. There is a problem that the heat loss rate is high.

2 is a process diagram of a hot gas waste heat recovery apparatus (application number 10-2002-0081552) of a conventional heat storage incinerator.

In detail, the cooling exhaust gas recovered and discharged from the waste heat recovery heat exchanger mentioned in FIG. 1 is directly circulated to the combustion chamber without releasing to the air, so that waste heat itself of about 41% can be recovered, thereby reducing heat dissipation loss. If neglected, the installation is very thermally efficient.

However, the gas cooled through the waste heat recovery heat exchanger is 350 ° C, which is much lower than the combustion chamber temperature of 850 ° C. When this cooling gas flows into the combustion chamber, the combustion chamber is lowered, and thus, the incineration efficiency is lowered to achieve the design incineration efficiency of the incinerator. There are no drawbacks.

In order to solve the above problems, the high temperature gas removed for the purpose of waste heat recovery from the combustion chamber is discharged to the atmosphere after being heat-exchanged to lower the thermal efficiency or directly into the combustion chamber so as not to reduce the incineration efficiency. It is an object of the present invention to provide a waste heat recovery apparatus applied to the heat storage incinerator having a.

In order to solve the above problems, the present invention is a device for recovering high-temperature waste heat of the heat storage incinerator consisting of a main blower, a heat storage layer, a combustion chamber for incineration of volatile organic compounds or odor gas, the high temperature state discharged from the combustion chamber A waste heat recovery heat exchanger for recovering heat of gas; A first circulation blower configured to circulate the cooled gas discharged from the combustion chamber to the front and rear ends of the waste heat recovery heat exchanger; It characterized in that it comprises a air volume control valve for controlling the flow rate of the gas passing through the waste heat recovery heat exchanger to join the suction side to the main blower installed in the inlet side of the heat storage type incinerator.

In addition, the present invention is a device for recovering the high-temperature waste heat of the heat storage incinerator in which the volatile organic compound or odor gas incinerated in the combustion chamber after passing through the heat storage layer through the main blower, to recover the high-temperature gas heat discharged from the combustion chamber Waste heat recovery heat exchanger; A first circulation blower configured to circulate the cooled gas discharged from the combustion chamber to the front and rear ends of the waste heat recovery heat exchanger; It characterized in that it comprises a second circulation blower for controlling the flow rate of the gas passing through the waste heat recovery heat exchanger to join the discharge side of the main blower installed at the inlet of the heat storage incinerator.

In addition, the present invention is attached to the suction side of the main blower pressure sensor for automatically adjusting the flow rate of the main blower; And a hood installed on the suction side of the main blower.

In addition, the present invention is a device for recovering the waste heat of the high temperature gas discharged from the combustion chamber in the apparatus for recovering the waste heat of the high temperature gas discharged from the combustion chamber in the apparatus for incineration of the volatile organic compound or odor gas through the main blower and passing through the heat storage layer in the combustion chamber Recovery heat exchanger; A first circulation blower configured to circulate the cooled gas discharged from the combustion chamber to the front and rear ends of the waste heat recovery heat exchanger; A second circulation blower configured to transfer the gas passed through the waste heat recovery heat exchanger to a lower portion of the heat storage layer in a purge step; A flow rate control valve installed between the second circulation blower and the waste heat recovery exchanger to adjust the amount of gas for waste heat recovery; A purge dedicated automatic valve operating in a waste heat recovery stopper provided in a conduit connecting the second circulation blower and the air flow control valve; It characterized in that it comprises a purge or circulation valve provided between the second circulation blower and each of the heat insulating layer.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

3 is a process diagram showing the waste heat recovery apparatus applied to the heat storage incinerator according to an embodiment of the present invention, Figure 4 is a process diagram showing the waste heat recovery apparatus applied to the heat storage incinerator according to another embodiment of the present invention.

The heat storage incinerator is composed of a heat storage layer filled with a heat storage medium in each bed that directly loses heat to the gas by directly contacting the gas, and a combustion chamber that incinerates volatile organic gas or odors. And a stack for exhausting the final exhaust gas to the atmosphere.

The basis of the practice of the present invention is the basic principle of a regenerative incinerator. That is, volatile organic compounds or odorous gases discharged from the production facility enter the combustion chamber while being preheated by directly contacting the heat-generated ceramic medium in the heat storage layer when the volatile organic compound or odor gas is introduced into the heat storage incinerator. At this time, the preheating temperature may vary depending on the heat storage efficiency design of the heat storage type incinerator, but is combined with the heat of combustion generated during the self-heating and is preheated to about the combustion chamber temperature (above 800 ℃). The preheated gas is completely incinerated in the combustion chamber and then heated to the ceramic medium while passing through another heat storage layer to heat the ceramic medium, while the exhaust gas is cooled down and passes through the final heat storage layer, typically 40 ° C above the initial inlet gas temperature. The heat storage efficiency is high enough that it is only high. That is, the temperature distribution of the heat storage incinerator installation is composed of inlet temperature 30 ℃, combustion chamber temperature 800 ℃, outlet temperature 70 ℃. The process of 30 degreeC gas becoming 800 degreeC is the waste gas preheating process, and the process of exhausting from 800 degreeC to 70 degreeC is the ceramic medium heat storage process.

The present invention relates to a waste heat recovery apparatus installed in a heat storage type incinerator, and the waste heat recovery apparatus includes a waste heat recovery heat exchanger (400), a first circulation blower (120), and a temperature sensor (520). In the case of circulating through the main blower suction side installed at the inlet of the regenerative incinerator as described above, the second circulation blower is circulated through the main blower discharge side installed at the inlet of the regenerative incinerator as shown in FIG. 4. 140 and the check valve 620 to re-inject the cooling gas after the waste heat recovery to the heat storage type incinerator (300).

The process principle of FIGS. 3, 4 and 5 is as follows.

The waste heat of the regenerative incinerator refers to the heat of combustion generated during the combustion of the organic gas and is a high temperature of 850 ° C. or higher. The process is configured to reuse this high temperature heat by heating the heat medium oil, steam or air. The flow of fluid first begins by moving hot gas to the waste heat recovery heat exchanger 400 in the combustion chamber 320 of the regenerative incinerator 300 in normal operation. The amount of this high temperature gas is configured to be automatically controlled according to the set temperature of the thermal fluid or reused fluid such as steam and air. However, as mentioned above, when the gas in the combustion chamber is supplied to the waste heat recovery heat exchanger 400 directly because it is in a very high temperature of more than 850 ° C., it may cause problems such as mechanical heat damage and thermal oil property change.

Accordingly, the gas cooled in the rear end of the waste heat recovery heat exchanger 400 is circulated to form a circulation line so as to be mixed with the hot gas of the heat chamber 320 and cooled, and a first circulation blower 120 is installed. The gas temperature in front of the waste heat recovery heat exchanger is about 500 ° C., and is used to heat the heat medium oil, steam, or air. After use, the cooled gas is partially circulated by the first circulation blower 120, and the remaining gas is about 350 ° C., so the system is configured to be circulated into the heat storage incinerator to recover it again. In this way, it is sent to the inlet of the regenerative incinerator, mixed with organic odor gas, preheated through the heat storage layers 200, 220, and 240 in the preheating stage, and the amount of organic gas incinerated after incineration in the combustion chamber 320 is stored in the heat storage process. After the exhaust gas is discharged to the atmosphere, the gas for waste heat recovery is circulated back to the waste heat recovery heat exchanger 400, and a step of purging the untreated gas remaining in the heat storage layer by using the purge gas is sent to the heat storage layer during the purge step. While performing, as it passes through the heat storage layer, it is configured in a way that is preheated and circulated to the combustion chamber (320).

 In this process, the hot gas that has been moved from the combustion chamber 320 to the waste heat recovery heat exchanger 400 is cooled and then circulated in the heat storage type incinerator itself without exhaust gas flowing into the atmosphere.

The amount of hot gas in the combustion chamber 320 supplied to the waste heat recovery is automatically controlled by the temperature of the thermometer 520 installed in a line such as thermal oil, steam, or air, and the air flow control valve 600 is used as an operation unit. Inverter control of the second circulation blower 140 may be selected.

3, when the exhaust gas cooled in the waste heat recovery heat exchanger 400 is connected to the front end of the main blower 100 installed at the inlet of the regenerative incinerator, the pressure of the regenerative incinerator combustion chamber 320 and the main blower 100 shear pressure Due to the difference in the flow pressure is generated, the exhaust gas can be moved without a separate transfer device, without installing a second circulation blower 600 separately, it is possible to install and operate only the air flow control valve 600, it is possible to reduce the investment cost.

When the exhaust gas cooled in the waste heat recovery heat exchanger 400 is connected to the rear end of the main blower 100 installed at the inlet of the heat storage type incinerator as shown in FIG. 4, the amount of waste heat recovered is large after the waste heat recovery. In order to reduce the capacity of the blower 100, a second transfer blower 140, which is a separate transfer device, is installed. In addition, a check valve or an automatic valve for preventing a backflow is installed at the rear end of the second circulation blower 140 to join the rear end of the main blower 100.

In the case of using the purge process of the heat storage type incinerator as shown in FIG. 5, the second circulation blower 140 sends the cooled gas after the waste heat recovery to the bottom of the heat storage layer in the purge step, and additionally purges the gas to the bottom of the heat storage layer. It will serve to supply. In other words, the gas cooled after waste heat recovery is circulated while using the purge gas instead of the purge gas used as the external air or the stack gas. The first heat storage layer purge and circulation valve 720, the second heat storage layer purge and circulation valve 740, and the third heat storage layer purge and circulation valve 740 were purge valves of the heat storage incinerator process, and are not separately installed. .

The purge dedicated automatic valve 700 is only in FIG. 5, and if the waste heat recovery is not performed, purge gas cannot be supplied when the air flow control valve 600 is closed. It was further configured to open and operate the normal purge process. As mentioned in the art, regenerative incinerators require a purge process. The purge gas of the purge process has been used by using external air or by collecting the gas discharged from the stack 640 to the outside. The purge gas was sent to the combustion chamber 320 by incineration of the untreated gas remaining in the heat storage layer, and then merged with the gas of the heat storage stage, passed through the heat storage layer, and finally discharged to the atmosphere. The cooling gas transferred through the circulation blower 140 is supplied to the lower portion of the heat storage layer, and the remaining untreated gas is sent to the combustion chamber, and in the process, it is preheated, introduced into the combustion chamber 320, incinerated, and then, the waste heat recovery heat exchanger 400. Will be cycled to).

In other words, it is different from the conventional purge process in that the purge gas is combined with the gas in the heat storage stage and the combustion chamber and is not discharged through the heat storage layer.

In the installation of the present invention, the amount of hot gas supplied from the combustion chamber 320 to the waste heat recovery heat exchanger 400 is changed when the heat amount of waste heat recovery is changed, and the first circulation blower at the rear end of the waste heat recovery heat exchanger 400 is also changed. Since the amount of circulating gas of 120 is fixed, the amount of cooled gas circulated to the inlet of the remaining heat storage type incinerator is changed. In the case of FIG. 3 joined to the front of the main blower, in the situation where the amount of cooled gas after the waste heat recovery is greatly changed, if the feed blow air volume of the main blower is fixed, the amount of organic odor gas at the front end of the hood 540 is changed from the main blower 100. It becomes difficult to collect constantly. Because of this, the conveying air volume of the main blower 100 should be configured to be adjusted according to the air volume change of the amount of cooling gas after the waste heat recovery flowing into the front of the main blower. In order to construct such a system, by installing the pressure gauge 500 in the pipe of the organic odor gas and setting it to maintain a constant pressure, the organic odor gas is not discharged through the hood 540 to the main blower 100. Allow it to be collected. Install an inverter to adjust the flow rate of the main blower (100).

In the case of FIG. 4, since the cooling gas is conveyed by the second circulation blower 140 and joined to the rear of the main blower 100 after the waste heat recovery, it does not cause a direct change in the main blower volume, but is organic in the rear of the main blower 100. Odor gas and the conveying gas of the second circulation blower are mixed and transferred to the inlet combustion chamber 320 under the heat storage layer of the preheating stage. The organic odor gas in the combustion chamber 320 is incinerated and then discharged from the top of the heat storage layer in the heat storage stage to the stack 640 through the bottom of the heat storage layer, and the corresponding gas amount of the cooled gas transferred to the second circulation blower is the combustion chamber. Separated from the organic odor gas at 320 is circulated to the waste heat recovery heat exchanger (400). At this time, the pressure loss in the heat storage layer (200, 220, 240) of the preheating step is changed according to the change in the amount of gas that is waste heat recovery. In other words, when the amount of waste heat recovery is large, the pressure odor is large when the organic odor gas is mixed to pass through the heat storage layer of the preheating stage, and when the amount of waste heat recovery is small, the pressure loss is small. When the main blower 100 increases such a pressure loss, the amount of organic odor gas discharged from the front end of the hood 540 is reduced. Therefore, an inverter system is constructed to increase the pressure of the main blower. The inverter can be adjusted by installing and controlling the pressure sensor 0 (500) of the organic odor gas pipe line.

Alternatively, by installing the hood 540 at the front end of the main blower 100 and adjusting the load of the inverter of the main blower 100 according to whether or not the organic odor gas is discharged from the hood 540, the amount of blowing is changed so that the organic matter is organic. Odor gas collection amount can be kept constant.

5, after the waste heat recovery, the cooling gas is mixed with the organic odor gas and does not flow into the heat storage layer of the preheating stage, and is separated into the heat storage layer of the purge stage and is circulated so that the main blower 100 is organic according to the amount of cooling gas after the waste heat recovery. There is no need for a separate system because it has little effect on the odor gas capture capacity.

In the heat storage type incinerator according to one embodiment of the present invention, in the process of using the high temperature waste heat, the cooled exhaust gas is circulated to the inlet side of the heat storage type incinerator or to the heat storage layer of the purge step without exhausting the cooled exhaust gas into the combustion chamber without being discharged to the atmosphere. The waste heat recovery rate can be increased at the same time without compromising the incinerator's original function.

Claims (4)

In the apparatus for recovering the high temperature waste heat of the heat storage type incinerator composed of the main blower, heat storage layer, combustion chamber for incineration of volatile organic compounds or odor gas, A waste heat recovery heat exchanger for recovering gas heat at a high temperature discharged from the combustion chamber; A first circulation blower configured to circulate the cooled gas discharged from the combustion chamber to the front and rear ends of the waste heat recovery heat exchanger; A flow rate control valve for controlling the flow rate of the gas passing through the waste heat recovery heat exchanger and joining the suction side to the main blower installed at the inlet side of the heat storage type incinerator; Waste heat recovery apparatus applied to the heat storage incinerator, characterized in that configured to include. An apparatus for recovering high-temperature waste heat of a regenerative incinerator in which a volatile organic compound or an odorous gas is incinerated in a combustion chamber through a main blower and a regenerative layer, A waste heat recovery heat exchanger for recovering gas heat at a high temperature discharged from the combustion chamber; A first circulation blower configured to circulate the cooled gas discharged from the combustion chamber to the front and rear ends of the waste heat recovery heat exchanger; A second circulation blower for controlling the flow rate of the gas passing through the waste heat recovery heat exchanger to join the discharge side of the main blower installed at the inlet of the heat storage incinerator; Waste heat recovery apparatus applied to the heat storage incinerator, characterized in that configured to include. The method according to claim 1 or 2, A pressure sensor attached to the suction side of the main blower and automatically adjusting the flow rate of the main blower; A hood installed on the suction side of the main blower; Waste heat recovery apparatus applied to the heat storage incinerator, characterized in that it further comprises. An apparatus for recovering high-temperature waste heat of a regenerative incinerator in which a volatile organic compound or an odorous gas is incinerated in a combustion chamber through a main blower and a regenerative layer, A waste heat recovery heat exchanger for recovering waste heat of the hot gas discharged from the combustion chamber; A first circulation blower configured to circulate the cooled gas discharged from the combustion chamber to the front and rear ends of the waste heat recovery heat exchanger; A second circulation blower configured to transfer the gas passed through the waste heat recovery heat exchanger to a lower portion of the heat storage layer in a purge step; A flow rate control valve installed between the second circulation blower and the waste heat recovery exchanger to control the amount of gas for waste heat recovery; A purge dedicated automatic valve operating in a waste heat recovery stopper provided in a conduit connecting the second circulation blower and the air flow control valve; A purge or circulation valve provided between the second circulation blower and each of the heat insulating layers; Waste heat recovery apparatus applied to the heat storage incinerator, characterized in that configured to include.

Images